.page-about {
  --about-rail: 200px;
  --about-stroke: rgba(30, 63, 55, 0.9);
}

.page-about .about-crumb {
  padding-top: 20px;
}

.page-about .about-crumb .crumb {
  margin: 0;
  font-size: 12px;
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  padding-top: 12px;
  padding-bottom: 72px;
}

/* ---------- 粘性编号索引 ---------- */
.page-about .about-index {
  position: sticky;
  top: 62px;
  z-index: 6;
  padding: 8px 0 6px;
  background: rgba(11, 31, 26, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-index__title {
  display: none;
}

.page-about .about-index__list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0 0 2px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-index__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-index__list a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 11px;
  border: 1px solid var(--line);
  background: rgba(18, 48, 42, 0.65);
  color: var(--mute);
  font-size: 12px;
  line-height: 1.2;
  letter-spacing: 0.06em;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--mist);
  border-color: var(--zone, var(--lime));
  background: rgba(23, 59, 51, 0.9);
  outline: none;
}

.page-about .about-index__num {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0;
  color: var(--zone, var(--lime));
}

/* ---------- 章节通用 ---------- */
.page-about .about-flow {
  min-width: 0;
}

.page-about .about-sec {
  position: relative;
  padding: 26px 0 10px;
  scroll-margin-top: 128px;
}

.page-about .about-sec + .about-sec {
  margin-top: 26px;
  padding-top: 40px;
}

.page-about .about-sec + .about-sec::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--line), rgba(30, 63, 55, 0) 88%);
  transform: skewY(-0.4deg);
  transform-origin: left center;
}

.page-about .about-sec__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 12px;
  align-items: start;
  margin-bottom: 22px;
}

.page-about .about-sec__no {
  grid-row: 1 / span 2;
  margin: 0;
  font-family: var(--f-mono);
  font-size: 28px;
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: var(--zone, var(--lime));
  opacity: 0.55;
}

.page-about .about-sec__title {
  margin: 0;
  font-family: var(--f-display);
  font-size: clamp(22px, 5vw, 34px);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--mist);
}

.page-about .about-sec__sub {
  grid-column: 2;
  margin: 8px 0 0;
  max-width: 58ch;
  color: var(--mute);
  font-size: 15px;
  line-height: 1.7;
}

/* ---------- 01 开篇 ---------- */
.page-about .about-sec--lead .about-sec__no {
  margin-bottom: 10px;
  font-size: 34px;
}

.page-about .about-lead__title {
  margin: 0 0 16px;
  font-family: var(--f-display);
  font-size: clamp(30px, 7.6vw, 58px);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--mist);
  max-width: 20ch;
}

.page-about .about-lead__text {
  margin: 0 0 24px;
  max-width: 62ch;
  color: var(--mute);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .about-lead__figure {
  position: relative;
  margin: 0 0 22px;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-lead__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 7 / 4;
  object-fit: cover;
}

.page-about .about-lead__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(118deg, rgba(11, 31, 26, 0.05) 55%, rgba(11, 31, 26, 0.62) 100%);
  pointer-events: none;
}

.page-about .about-lead__figure figcaption {
  position: relative;
  z-index: 1;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  background: var(--ink-deep);
  color: var(--mute);
  font-size: 12px;
  line-height: 1.6;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-facts > div {
  padding: 14px 12px 16px;
  background: var(--ink-deep);
}

.page-about .about-facts dt {
  color: var(--mute);
  font-size: 11px;
  line-height: 1.5;
  letter-spacing: 0.1em;
}

.page-about .about-facts dd {
  margin: 8px 0 0;
  font-family: var(--f-mono);
  font-size: 22px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--lime);
}

/* ---------- 02 时间轴 ---------- */
.page-about .about-rail__figure {
  margin: 0 0 22px;
  border: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-rail__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12 / 7;
  object-fit: cover;
}

.page-about .about-rail {
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 12px;
  scroll-snap-type: x proximity;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail::-webkit-scrollbar {
  height: 2px;
}

.page-about .about-rail::-webkit-scrollbar-thumb {
  background: var(--line);
}

.page-about .about-rail:focus-visible {
  outline: 2px solid var(--zone, var(--lime));
  outline-offset: 6px;
}

.page-about .about-rail__list {
  display: flex;
  gap: 14px;
  margin: 0;
  padding: 18px 0 0;
  list-style: none;
}

.page-about .about-rail__item {
  position: relative;
  flex: 0 0 252px;
  padding: 18px 0 0;
  border-top: 2px solid var(--line);
  scroll-snap-align: start;
}

.page-about .about-rail__item::before {
  content: "";
  position: absolute;
  top: -6px;
  left: 0;
  width: 10px;
  height: 10px;
  background: var(--zone, var(--lime));
  transform: rotate(45deg);
}

.page-about .about-rail__ver {
  display: block;
  font-family: var(--f-mono);
  font-size: 32px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--zone, var(--lime));
}

.page-about .about-rail__item h3 {
  margin: 10px 0 6px;
  font-family: var(--f-display);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--mist);
}

.page-about .about-rail__item p {
  margin: 0;
  color: var(--mute);
  font-size: 14px;
  line-height: 1.72;
}

/* ---------- 03 内容中心 ---------- */
.page-about .about-quad {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-quad__item {
  padding: 18px 18px 20px;
}

.page-about .about-quad__item h3 {
  margin: 12px 0 8px;
  font-family: var(--f-display);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--mist);
}

.page-about .about-quad__item p {
  margin: 0;
  color: var(--mute);
  font-size: 14px;
  line-height: 1.75;
}

/* ---------- 04 统计同步 ---------- */
.page-about .about-check__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 18px;
}

.page-about .about-check__stat {
  padding: 14px 12px 16px;
  background: linear-gradient(160deg, var(--panel), rgba(7, 22, 18, 0.9));
  border: 1px solid var(--line);
  border-left: 3px solid var(--zone, var(--lime));
}

.page-about .about-check__stat b {
  display: block;
  font-family: var(--f-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--zone, var(--lime));
}

.page-about .about-check__stat span {
  display: block;
  margin-top: 8px;
  color: var(--mute);
  font-size: 12px;
  line-height: 1.55;
  letter-spacing: 0.04em;
}

.page-about .about-fields {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 18px;
  padding: 0;
  list-style: none;
}

.page-about .about-fields li {
  padding: 6px 12px;
  border: 1px solid var(--line);
  background: var(--ink-deep);
  color: var(--mist);
  font-family: var(--f-mono);
  font-size: 13px;
  line-height: 1.4;
}

.page-about .about-check__note {
  margin: 0;
  max-width: 62ch;
  color: var(--mute);
  font-size: 14px;
  line-height: 1.8;
}

/* ---------- 05 团队分工 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-team__media {
  margin: 0;
  border: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-team__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
}

.page-about .about-team__card {
  padding: 16px 16px 6px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 2px solid var(--zone, var(--lime));
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-team__card:hover,
.page-about .about-team__card:focus,
.page-about .about-team__card:focus-visible {
  transform: translateY(-4px);
  border-color: var(--zone, var(--lime));
  outline: none;
}

.page-about .about-team__card h3 {
  margin: 10px 0 6px;
  font-family: var(--f-display);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--mist);
}

.page-about .about-team__card > p {
  margin: 0 0 10px;
  color: var(--mute);
  font-size: 14px;
  line-height: 1.72;
}

.page-about .about-team__more {
  max-height: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow: hidden;
  opacity: 0;
  transition: max-height 260ms var(--ease), opacity 200ms var(--ease),
    padding-bottom 260ms var(--ease);
}

.page-about .about-team__card:hover .about-team__more,
.page-about .about-team__card:focus-within .about-team__more,
.page-about .about-team__card:focus .about-team__more {
  max-height: 420px;
  opacity: 1;
  padding-bottom: 14px;
}

.page-about .about-team__more li {
  position: relative;
  margin-top: 6px;
  padding-left: 14px;
  color: var(--mist);
  font-size: 13px;
  line-height: 1.62;
}

.page-about .about-team__more li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 6px;
  height: 6px;
  background: var(--zone, var(--lime));
  transform: rotate(45deg);
}

.page-about .about-team__note {
  margin: 18px 0 0;
  max-width: 62ch;
  color: var(--mute);
  font-size: 14px;
  line-height: 1.8;
}

/* ---------- 06 服务标准 ---------- */
.page-about .about-rules {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
}

.page-about .about-rules li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding: 13px 15px;
  background: linear-gradient(90deg, var(--panel), rgba(18, 48, 42, 0.28));
  border-left: 2px solid var(--zone, var(--lime));
  color: var(--mist);
  font-size: 14px;
  line-height: 1.68;
}

.page-about .about-rules b {
  font-family: var(--f-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--zone, var(--lime));
  white-space: nowrap;
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-quad {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-rules {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-check__stat b {
    font-size: 30px;
  }
}

@media (min-width: 760px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-check__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-sec__no {
    font-size: 34px;
  }

  .page-about .about-rail__item {
    flex: 0 0 280px;
  }
}

@media (min-width: 900px) {
  .page-about .about-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .about-team__media {
    grid-column: 1 / -1;
  }
}

@media (min-width: 960px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 52px;
    padding-top: 34px;
    padding-bottom: 96px;
  }

  .page-about .about-index {
    top: 128px;
    align-self: start;
    padding: 0 0 0 2px;
    background: none;
    backdrop-filter: none;
    border-bottom: 0;
  }

  .page-about .about-index__title {
    display: block;
    margin: 0 0 12px;
    color: var(--mute);
    font-size: 11px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-index__list a {
    justify-content: flex-start;
    width: 100%;
    padding: 9px 10px 9px 12px;
    border: 0;
    border-left: 2px solid var(--line);
    background: none;
    font-size: 13px;
  }

  .page-about .about-index__list a:hover,
  .page-about .about-index__list a:focus-visible {
    border-left-color: var(--lime);
    background: none;
  }

  .page-about .about-sec {
    padding: 8px 0 12px;
    scroll-margin-top: 150px;
  }

  .page-about .about-sec + .about-sec {
    margin-top: 44px;
    padding-top: 56px;
  }

  .page-about .about-sec__head {
    gap: 6px 18px;
    margin-bottom: 26px;
  }

  .page-about .about-sec__no {
    font-size: 40px;
  }

  .page-about .about-sec__sub {
    font-size: 16px;
  }

  .page-about .about-lead__title {
    font-size: clamp(38px, 4.4vw, 58px);
  }

  .page-about .about-lead__text {
    font-size: 17px;
  }

  .page-about .about-lead__figure {
    margin-bottom: 26px;
  }

  .page-about .about-facts dd {
    font-size: 26px;
  }

  .page-about .about-rail__item {
    flex: 0 0 300px;
  }

  .page-about .about-rail__ver {
    font-size: 38px;
  }

  .page-about .about-quad__item {
    padding: 22px 22px 24px;
  }

  .page-about .about-check__note,
  .page-about .about-team__note {
    font-size: 15px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-layout {
    gap: 64px;
  }

  .page-about .about-rail__item {
    flex: 0 0 320px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__list a,
  .page-about .about-team__card,
  .page-about .about-team__more {
    transition: none;
  }

  .page-about .about-team__card:hover,
  .page-about .about-team__card:focus {
    transform: none;
  }
}
</main>